Abstract

The extravagant crests, tails, colors, and songs of many animals, particularly males, have long puzzled evolutionary biologists. The peacock’s colorful tail is a classic example. This tail, which can reach more than five feet in length, requires a great deal of energy to grow, and it is a burden to lug around for most of the year. Why, then, should the tail have evolved? Natural selection is supposed to favor traits that make organisms more fit, not less fit.